Proteasome activity is important for replication recovery, CHK1 phosphorylation and prevention of G2 arrest after low-dose formaldehyde.
Proteasome activity is important for replication recovery, CHK1 phosphorylation and prevention of G2 arrest after low-dose formaldehyde.
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蛋白酶体活性对于复制恢复、CHK1 磷酸化和防止低剂量甲醛后 G2 停滞非常重要。
DOI：
10.1016/j.taap.2015.03.018
复制
发表时间：
2015
影响因子：
3.8
通讯作者：
Zhitkovich,Anatoly
中科院分区：
文献类型：
--
作者：
Ortega-Atienza,Sara;Green,SamanthaE;Zhitkovich,Anatoly
甲醛（FA）是一种人类致癌物，有多种环境和职业暴露来源。这种活性醛也在药物代谢和其他过程中内源性产生。DNA-蛋白质交联（DPC）被认为是FA的主要遗传毒性病变。越来越多的证据表明，在高等真核生物中DPC修复涉及交联蛋白的蛋白水解。在这里，我们研究了主要的细胞蛋白水解机制蛋白酶体在人肺细胞对低剂量FA的毒性反应中的作用。我们发现，蛋白酶体活性的瞬时抑制增加细胞毒性和减少FA处理的细胞的克隆形成能力。蛋白酶体失活加剧了FA对DNA复制的抑制作用，并增加了正常人细胞中遗传毒性应激标志物γ-H2 AX的水平。FA暴露细胞中蛋白酶体活性的短暂丧失也引起细胞周期的延迟扰动，其中包括G2期阻滞和FA剂量下S期群体的耗竭，而这些在对照细胞中没有影响。蛋白酶体活性降低p53-Ser 15磷酸化，但对FA诱导的CHK 1磷酸化很重要，CHK 1磷酸化是复制细胞中DPC蛋白水解的生化标志。与FA不同，蛋白酶体抑制对细胞存活和CHK 1磷酸化没有影响，由非DPC复制应激物羟基脲。总的来说，我们获得了蛋白酶体在保护人类细胞免受生物学相关剂量的FA的重要性的证据。生化方面，我们的研究结果表明蛋白酶体参与DPC的蛋白水解修复，这消除了这些高度庞大的病变的复制障碍。
Formaldehyde (FA) is a human carcinogen with numerous sources of environmental and occupational exposures. This reactive aldehyde is also produced endogenously during metabolism of drugs and other processes. DNA–protein crosslinks (DPCs) are considered to be the main genotoxic lesions for FA. Accumulating evidence suggests that DPC repair in high eukaryotes involves proteolysis of crosslinked proteins. Here, we examined a role of the main cellular proteolytic machinery proteasomes in toxic responses of human lung cells to low FA doses. We found that transient inhibition of proteasome activity increased cytotoxicity and diminished clonogenic viability of FA-treated cells. Proteasome inactivation exacerbated suppressive effects of FA on DNA replication and increased the levels of the genotoxic stress marker γ-H2AX in normal human cells. A transient loss of proteasome activity in FA-exposed cells also caused delayed perturbations of cell cycle, which included G2 arrest and a depletion of S-phase populations at FA doses that had no effects in control cells. Proteasome activity diminished p53-Ser15 phosphorylation but was important for FA-induced CHK1 phosphorylation, which is a biochemical marker of DPC proteolysis in replicating cells. Unlike FA, proteasome inhibition had no effect on cell survival and CHK1 phosphorylation by the non-DPC replication stressor hydroxyurea. Overall, we obtained evidence for the importance of proteasomes in protection of human cells against biologically relevant doses of FA. Biochemically, our findings indicate the involvement of proteasomes in proteolytic repair of DPC, which removes replication blockage by these highly bulky lesions.
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DOI：
10.1073/pnas.0600538103
发表时间：
2006-03-14
影响因子：
11.1
作者：
Reardon, JT;Sancar, A
通讯作者：
Sancar, A
抗肿瘤氮的DNA-蛋白交联的蛋白质组学分析。
影响因子：
4.1
作者：
Loeber, Rachel L.;Michaelson-Richie, Erin D.;Codreanu, Simona G.;Liebler, Daniel C.;Campbell, Colin R.;Tretyakova, Natalia Y.
通讯作者：
Tretyakova, Natalia Y.
影响因子：
4.1
作者：
Macfie, Andrea;Hagan, Elizabeth;Zhitkovich, Anatoly
通讯作者：
Zhitkovich, Anatoly
影响因子：
16.8
作者：
Toledo LI;Murga M;Zur R;Soria R;Rodriguez A;Martinez S;Oyarzabal J;Pastor J;Bischoff JR;Fernandez-Capetillo O
通讯作者：
Fernandez-Capetillo O
影响因子：
3.8
作者：
Lu, Kun;Collins, Leonard B.;Swenberg, James A.
通讯作者：
Swenberg, James A.